This invention relates to an inking arrangement used for a printing machine and is particularly concerned with an inking arrangement for feeding a printing ink to a plate cylinder.
In an inking arrangement used for a printing machine, a printing ink stored in an inkwell is transferred to ink applying rollers from an ink delivery roller through a train of inking rollers, and the printing ink is then scoured to a plate such as a plate cylinder or the like from the ink applying rollers.
In a prior art inking arrangement, a printing ink stored in an inkwell is extracted on an ink delivery roller and then guided to an inking roller train including a plurality of inking rollers combined therefor. The inking roller train comprises, in combination, an ink transfer roller for transferring the extracted printing ink in a proper quantity, scouring rollers for securing a fluidity of the printing ink by minimizing a change in concentration thereof, reciprocating rollers reciprocating axially at a constant width to distribute the printing ink uniformly without causing inhomogeneous regions, and ink applying rollers for settling the printing onto a scanning area of a plate such as a plate cylinder. In consideration of scour and transferability of the printing ink, the inking roller train includes metallic rollers and rubber rollers disposed alternately, thus aiding in achieving keeping the printing ink constant in concentration.
In a printing machine such as a sheet press, web press of the like, an inking arrangement in which a plate cylinder or the like is incorporated is set, a printing ink is scoured by the inking arrangement and applied to the plate cylinder, a printing paper is fed to the plate cylinder to which the ink is applied, and a pressure is applied to effect the paper to printing.
In the prior art inking arrangement, a plurality of inking rollers are combined to form a system linking the ink transfer roller to the ink applying rollers, and a printing ink is scoured by the inking roller train, thereby keeping the printing ink applied to the plate cylinder constant in concentration.
However, in the prior art inking arrangement, while the printing ink is transferred in succession to a lower stage side through the inking roller train, it is difficult to transfer the ink thoroughly to the inking rollers on the lower stage side, and thus there may be a case where the printing ink which could not be transferred to the inking roller on the lower stage side remains on a surface of the inking roller for applying the printing ink to the plate cylinder. The residual ink is introduced onto the plate cylinder, resulting in an unevenness in concentration of the printing ink, which may cause an non-homogeneous printing and an ink stain.